Amiga famously used a version of hardware backed delta encoding [1] to display more colours on the screen than normally possible within its memory limits.
HAM would have worked even better if it had been in the intended hue-saturation-value (HSV) colour space as Jay Miner originally intended. Sadly, HSV support was dropped, but due to schedule constraints, there wasn't enough time to rework the design and remove HAM. I found it fascinating to learn these things long after I was no longer using my Amiga for day to day work.
Amiga famously used a version of hardware backed delta encoding [1] to display more colours on the screen than normally possible within its memory limits.
[1] https://en.wikipedia.org/wiki/Hold-And-Modify